Hi Herbert,
The easiest way that I have found to do over dubs in sequencing, is to place the sound and the volume setting in the mixer prior to starting your recording. I generally set the volume high so I can hear the sound clearly when making the second or third pass. It’s then possible to go back and adjust the sound so the mix is just as you want it. I’ve stopped using the expression pedal when sequencing because I’ve found that the sequencer doesn’t do a good job of recording the pedal data. While it’s possible to go back and edit the control track to make corrections, the procedure is tedious. To create the effect of expression I use the velocity with which I strike the keys to gain the effect.
Frank